Choke valve control



Jan. 6, 1953 H. A. BOLLER 2,624,363

cHoKE VALVE CONTROL Filed May 1, 1947 ATTORNEY Patented Jan. 6, 1953 CHOKE VALVE CONTROL Henry A. Boller, Pontiac, Mich., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application May 1, 1947, Serial No. '745,273` 3 Claims. (Cl. 137-481) This invention relates to carburetors for internal combustion engines of the automotive type and consists particularly in a novel manual choke valve control therefor. y

A familiar form of ,manual choke control; as now used with the Chevrolet carburetor, comprises a lever loosely journalled on the choke shaft and connected to the shaft by a spring whereby the choke is closed through the spring. Even in its fully closed position, the unbalanced chokeis free to breathe against the spring under ther influence Vof air flow applied directly thereto. A diiculty with this choke has been that, in' some instances, the valve sticks in its wide open position and thertension of the spring has not been sullcient to dislodge the valve.

Accordingly, an object of the present invention is to provide an additional feature in the above type of choke control whereby in case of sticking of the choke valve in wide open position, means is provided to positively initiate the closing movement thereof.

A more detailed Vobject 'is to provide a choke control lever having a part disposed to strike a projection from the choke shaft just prior to the extreme movement of the lever in the choke closing direction to positively dislodge the choke in case of its sticking in the wide open position.

The above objects and others are attained by the structure illustrated in the accompanying drawing in which Fig. l is a side view of an -automotive `carburetor embodying the invention.

Fig. 2 is a similar view of the upper part of the carburetor showing the parts in a diiferent position and the fast idle link partly brokeny away.

Fig. 3 is a view similar to Fig. 2 but showing the parts in a, third position.

Fig. 4 is a detail section on line 4 4 of Fig. 1.

The carburetor is of the downdraft type including an air inlet horn 6 in the walls of which there is journalled a choke draft 1 carrying an unbalanced butterily choke valve 3. Discharge from the lower end of the mixture barrel is controlled by a butterfly throttle valve 9 on a shaft I having a control lever I I rigid therewith. An adjusting screw I2 mounted in lever II is positioned to engage a link I3 journalled at its lower extremity on a boss I4 surrounding throttle shaft I0 to establish the idling position of the throttle valve. The upper end of link I3 has an inclined clevis I3a receiving a pin I5 on choke operating lever I6.

Lever I6 is journalled on boss I'I projecting from air horn 6 and has an aperture I8 for connection to a rod or Bowden cable extending to the operators compartment. Ihe extremity of choke shaft 1 extending through bossv II rigidly mounts asmall disk I9 having a radial projection 26 with an inwardly oifset lip 2| which overlies lever I6. A torsion spring 22 received about boss II has its extremities hooked about lip 2I and the lever, as at 23 and 24 and normally maintains this lip in engagement with a shoulder 25 on the lever. Thus, thespring resists opening movement only of the valve relative to the lever. A stop 26 formed on the inside wall of theair horn limits the fully open position of the choke valve while the walls of the inlet itself limit the closed position of the valve. An additional stop pin 2l on the outer wall of the air horn is engaged by lever It just as the choke valve is fully closed so that the actuation of lever lrwhen the engine is not in operation, as in `closing the choke for starting, does not affect the tension of spring 22.

Since theY closing movement, of the choke is effected through spring 22, the tension of this spring may not be suiiicient to dislodge the choke in case it sticks in its wide open position. Accordingly, a second shoulder 28 is provided on lever I6 opposite to and radially spaced from shoulder 25. Second shoulder 28 is disposed so that just prior to engagement of stop 2l by lever I6, the shoulder will strike lip 2| to dislodge the choke and initiate its closing movement. The balance of the choke closing movement, of course. is effected through spring 22 in the normal manner.

Fast idle link I3 is controlled with manual lever I6 to provide normal and fast idling positions of the throttle, respectively, when the choke valve is fully opened and closed.

In operation, choke lever I6 will be fully rotated in its counterclockwise direction, to the position shown in Fig. 3, for cold starting. In this position, opening of the unbalanced choke valve is resisted by torsion spring 22. After the engine starts to run, the choke lever will be returned slowly to its full open position, as shown in Fig. l, the choke valve, of course, also being moved to the full open position, but in the intermediate positions of the choke lever, being free to open farther under the influence of direct air flow, until it strikes stop 26. In case the choke valve should stick in its wide open position of Fig. 1, full counterclockwise rotation of choke lever I6 until it strikes stop pin 21, will cause shoulder 28 on the lever to initiate the choke closing movement, as indicated in Fig. 2. However, even in this position of the choke lever, the choke valve is free to move substantially to its full open position.

Accordingly, means is provided for positively dislodging the choke in case of sticking without otherwise affecting the operation of the choke control. The invention may be modified in various respects as Will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. In a carburetor having an air inlet, an vunbalanced butterfly choke valve mounted on a shaft in said inlet, stop structure on thewall of said inlet limiting the openingand closing movements of said valve, a lever journaled about said shaft, a radial shoulder on said shaft adjacent said lever, a spring connecting said shaft and lever and normally holding said shaft shoulder against said lever so as to resist opening of said valve relative to said lever, and a stop limiting the valve closing Vmovement of said vlever `to `a position to just close said valve, said lever having a part disposed to forcefully strike said shaft shoulder in case f sticking of said valve to initiate the closing movement thereof ,l said striking part of said lever being arranged with respect to said shaft Shoulder and said stop toperrnit unobstructed movement of said shaft and said choke valve to a-substantially fully opened 'position regardless of the positionof said lever.

2. In a carburetor having an air inlet, an unbalanced choke valve mounted on a shaftin-said inlet, said shaft having a rigid radial projection, a lever journaled about said shaft and having a one-way connection therewith including said projection for joint opening movement of said valve and lever, a spring connecting said shaft and lever and resisting opening movement of said Valve relative to said lever whereby Vclosing of said valve is effected through said spring, stop structure on said inlet for determining the lfully open'and fully closed positions of said valve, and an additional stop on said inlet limiting the valve closing movement of lsaid lever, said lever having a rigid part for striking said shaft portion just prior to engagement of said additional stop by said lever, in case of sticking of said valve in wide open position, to initiate the closing movement of said Valve, said Striking part of said lever being arranged with resp-ect to said shaft shoulder and said stop to permit unobstructed movement of said shaft and said choke valve to a substantially fully opened position regardless of the position of said lever.

3. In a carburetor having an air inlet, an unbalanced butterfly choke valve mounted on a v shaft journaled in the walls of said inlet, a lever journaled about said shaft outside said inlet, said lever having rst and second radially spaced shoulders, a projection on said shaft between said shoulders, a spring connecting said shaft and lever and-normally maintaining said projection in engagement with said rst shoulder so as to yieldingly resist opening movement of said valve relative to said lever, stop structure on the wall of said inlet limiting the fully open and fully closed positions of said valve and also limiting thelclosing movement of said lever, the closing movement of said valve normally Ybeing effected through said spring and said second shoulder on said lever being disposed to strike said shaft projection as said lever approaches said last mentioned stop to initiate closing movement of said valve in case of sticking thereof in wide open position, said second shoulder'being arranged withrespectrto said shaft shoulder and said stop structure Vto permit unobstructed movement of said shaft-and said choke valve to a substantially fully opened position regardless of the position of said lever.

HENRY A. BOLLER.

REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 1,966,201 Firth July 10, 1934 2,017,890 Bracke Oct. 22,1935 2,065,167 Wirth Dec. 22,1936 2,192,703 Boller Mar. 5, 1940 2,322,109 Bimberg June 15, Y1948 

